Commit Graph

160 Commits

Author SHA1 Message Date
Uday Bondhugula af5e83f569 [MLIR] Introduce utility to hoist affine if/else conditions
This revision introduces a utility to unswitch affine.for/parallel loops
by hoisting affine.if operations past surrounding affine.for/parallel.
The hoisting works for both perfect/imperfect nests and in the presence
of else blocks. The hoisting is currently to as outermost a level as
possible.  Uses a test pass to test the utility.
Add convenience method Operation::getParentWithTrait<Trait>.

Depends on D77487.

Differential Revision: https://reviews.llvm.org/D77870
2020-04-16 00:32:34 +05:30
River Riddle 8938dea44a [mlir][IR] Manually register command line options for MLIRContext and AsmPrinter
Summary: This revision makes the registration of command line options for these two files manual with `registerMLIRContextCLOptions` and `registerAsmPrinterCLOptions` methods. This removes the last remaining static constructors within lib/.

Differential Revision: https://reviews.llvm.org/D77960
2020-04-11 23:13:00 -07:00
Stephen Neuendorffer 4956871c0e [MLIR] CMake cleanup for mlir-opt
A few libraries which are also Dialect libraries where independently
in the link line for mlir-opt.  Remove them.

Differential Revision: https://reviews.llvm.org/D77927
2020-04-11 22:02:16 -07:00
Nicolas Vasilache 6fb6a4d7f9 [mlir][Linalg] Add a test for a fused Linalg pass based on DRR to go from matmul to vectors
This revision builds a simple "fused pass" consisting of 2 levels of tiling, memory promotion and vectorization using linalg transformations written as composable pattern rewrites.
2020-04-08 16:54:40 -04:00
Lukas Sommer d86ece13d9 Keep output file after successful execution of mlir-opt
Invoke `keep()` on the output file of `mlir-opt` in case the invocation of `MlirOptMain` was successful, to make sure the output file is not deleted on exit from `mlir-opt`.
Fixes a similar problem in `standalone-opt` from the example for an out-of-tree, standalone MLIR dialect.

This revision also adds a missing parameter to the invocation of `MlirOptMain` in `standalone-opt`.

Differential Revision: https://reviews.llvm.org/D77643
2020-04-08 03:37:45 +00:00
Stella Laurenzo f5deb0878d Remove FxpMathOps dialect and Quantizer tool.
Summary:
* Removal of FxpMathOps was discussed on the mailing list.
* Will send a courtesy note about also removing the Quantizer (which had some dependencies on FxpMathOps).
* These were only ever used for experimental purposes and we know how to get them back from history as needed.
* There is a new proposal for more generalized quantization tooling, so moving these older experiments out of the way helps clean things up.

Subscribers: mgorny, mehdi_amini, rriddle, jpienaar, burmako, shauheen, antiagainst, nicolasvasilache, arpith-jacob, mgester, lucyrfox, liufengdb, Joonsoo, grosul1, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D77479
2020-04-07 13:22:39 -07:00
Mehdi Amini b8c260c38d Remove linking all targets from `mlir-opt` (NFC)
There is no need to directly depends on this from mlir-opt, some library
may transitively depend on a subset of the targets when enabled (like
NVPTX for Cuda codegen tests) but this is handled by CMake already.
2020-04-01 17:21:07 +00:00
Mehdi Amini bab5bcf8fd Add a flag on the context to protect against creation of operations in unregistered dialects
Differential Revision: https://reviews.llvm.org/D76903
2020-03-30 19:37:31 +00:00
Uday Bondhugula f273e5c507 [MLIR] Fix permuteLoops utility
Rewrite mlir::permuteLoops (affine loop permutation utility) to fix
incorrect approach. Avoiding using sinkLoops entirely - use single move
approach. Add test pass.

This fixes https://bugs.llvm.org/show_bug.cgi?id=45328

Depends on D77003.

Signed-off-by: Uday Bondhugula <uday@polymagelabs.com>

Differential Revision: https://reviews.llvm.org/D77004
2020-03-30 23:38:23 +05:30
Marcel Koester 86bbbb317b [mlir] Extended Dominance analysis with a function to find the nearest common dominator of two given blocks.
The Dominance analysis currently misses a utility function to find the nearest common dominator of two given blocks. This is required for a huge variety of different control-flow analyses and transformations. This commit adds this function and moves the getNode function from DominanceInfo to DominanceInfoBase, as it also works for post dominators.

Differential Revision: https://reviews.llvm.org/D75507
2020-03-27 14:55:40 +01:00
River Riddle e8f5c072f6 [mlir] Move the testing pass for GpuKernelToCubin to the test/ directory
Summary:
This removes the static pass registration, and also cleans up some lingering technical debt.

Differential Revision: https://reviews.llvm.org/D76554
2020-03-22 03:38:09 -07:00
River Riddle e74961eee2 [mlir][NFC] Remove Analysis/Passes.h
Summary:
This file only contains references to test passes, and was never removed when the test passes were moved to the test/ directory.

Differential Revision: https://reviews.llvm.org/D76553
2020-03-22 03:16:51 -07:00
Rob Suderman e708471395 [mlir][NFC] Cleanup AffineOps directory structure
Summary:
Change AffineOps Dialect structure to better group both IR and Tranforms. This included extracting transforms directly related to AffineOps. Also move AffineOps to Affine.

Differential Revision: https://reviews.llvm.org/D76161
2020-03-20 14:23:43 -07:00
Stephen Neuendorffer accede537e [MLIR] Link MLIRMlirOptMain with the same libraries as mlir-opt
MLIRMlirOptMain seems to need the same libraries as mlir-opt.

Differential Revision: https://reviews.llvm.org/D75783
2020-03-11 12:02:10 -07:00
River Riddle f8923584da [mlir][SideEffects] Define a set of interfaces and traits for defining side effects
This revision introduces the infrastructure for defining side-effects and attaching them to operations. This infrastructure allows for defining different types of side effects, that don't interact with each other, but use the same internal mechanisms. At the base of this is an interface that allows operations to specify the different effect instances that are exhibited by a specific operation instance. An effect instance is comprised of the following:

* Effect: The specific effect being applied.
  For memory related effects this may be reading from memory, storing to memory, etc.

* Value: A specific value, either operand/result/region argument, the effect pertains to.

* Resource: This is a global entity that represents the domain within which the effect is being applied.

MLIR serves many different abstractions, which cover many different domains. Simple effects are may have very different context, for example writing to an in-memory buffer vs a database. This revision defines uses this infrastructure to define a set of initial MemoryEffects. The are effects that generally correspond to memory of some kind; Allocate, Free, Read, Write.

This set of memory effects will be used in follow revisions to generalize various parts of the compiler, and make others more powerful(e.g. DCE).

This infrastructure was originally proposed here:
https://groups.google.com/a/tensorflow.org/g/mlir/c/v2mNl4vFCUM

Differential Revision: https://reviews.llvm.org/D74439
2020-03-06 14:04:36 -08:00
Valentin Churavy 7c64f6bf52 [MLIR] Add support for libMLIR.so
Putting this up mainly for discussion on
how this should be done. I am interested in MLIR from
the Julia side and we currently have a strong preference
to dynamically linking against the LLVM shared library,
and would like to have a MLIR shared library.

This patch adds a new cmake function add_mlir_library()
which accumulates a list of targets to be compiled into
libMLIR.so.  Note that not all libraries make sense to
be compiled into libMLIR.so.  In particular, we want
to avoid libraries which primarily exist to support
certain tools (such as mlir-opt and mlir-cpu-runner).

Note that the resulting libMLIR.so depends on LLVM, but
does not contain any LLVM components.  As a result, it
is necessary to link with libLLVM.so to avoid linkage
errors. So, libMLIR.so requires LLVM_BUILD_LLVM_DYLIB=on

FYI, Currently it appears that LLVM_LINK_LLVM_DYLIB is broken
because mlir-tblgen is linked against libLLVM.so and
and independent LLVM components.

Previous version of this patch broke depencies on TableGen
targets.  This appears to be because it compiled all
libraries to OBJECT libraries (probably because cmake
is generating different target names).  Avoiding object
libraries results in correct dependencies.

(updated by Stephen Neuendorffer)

Differential Revision: https://reviews.llvm.org/D73130
2020-03-06 13:25:18 -08:00
Stephen Neuendorffer 1c82dd39f9 [MLIR] Ensure that target_link_libraries() always has a keyword.
CMake allows calling target_link_libraries() without a keyword,
but this usage is not preferred when also called with a keyword,
and has surprising behavior.  This patch explicitly specifies a
keyword when using target_link_libraries().

Differential Revision: https://reviews.llvm.org/D75725
2020-03-06 09:14:01 -08:00
Stephen Neuendorffer 798e661567 Revert "[MLIR] Move from using target_link_libraries to LINK_LIBS for llvm libraries."
This reverts commit 7a6c689771.
This breaks the build with cmake 3.13.4, but succeeds with cmake 3.15.3
2020-02-29 11:52:08 -08:00
Stephen Neuendorffer dd046c9612 Revert "[MLIR] Add support for libMLIR.so"
This reverts commit e17d9c11d4.
It breaks the build.
2020-02-29 11:09:21 -08:00
Valentin Churavy e17d9c11d4 [MLIR] Add support for libMLIR.so
Putting this up mainly for discussion on
how this should be done. I am interested in MLIR from
the Julia side and we currently have a strong preference
to dynamically linking against the LLVM shared library,
and would like to have a MLIR shared library.

This patch adds a new cmake function add_mlir_library()
which accumulates a list of targets to be compiled into
libMLIR.so.  Note that not all libraries make sense to
be compiled into libMLIR.so.  In particular, we want
to avoid libraries which primarily exist to support
certain tools (such as mlir-opt and mlir-cpu-runner).

Note that the resulting libMLIR.so depends on LLVM, but
does not contain any LLVM components.  As a result, it
is necessary to link with libLLVM.so to avoid linkage
errors. So, libMLIR.so requires LLVM_BUILD_LLVM_DYLIB=on

FYI, Currently it appears that LLVM_LINK_LLVM_DYLIB is broken
because mlir-tblgen is linked against libLLVM.so and
and independent LLVM components.

Previous version of this patch broke depencies on TableGen
targets.  This appears to be because it compiled all
libraries to OBJECT libraries (probably because cmake
is generating different target names).  Avoiding object
libraries results in correct dependencies.

(updated by Stephen Neuendorffer)

Differential Revision: https://reviews.llvm.org/D73130
2020-02-29 10:47:27 -08:00
Stephen Neuendorffer 7a6c689771 [MLIR] Move from using target_link_libraries to LINK_LIBS for llvm libraries.
When compiling libLLVM.so, add_llvm_library() manipulates the link libraries
being used.  This means that when using add_llvm_library(), we need to pass
the list of libraries to be linked (using the LINK_LIBS keyword) instead of
using the standard target_link_libraries call.  This is preparation for
properly dealing with creating libMLIR.so as well.

Differential Revision: https://reviews.llvm.org/D74864
2020-02-29 10:47:26 -08:00
Stephen Neuendorffer dc1056a3f1 Revert "[MLIR] Move from using target_link_libraries to LINK_LIBS for llvm libraries."
This reverts commit 2f265e3528.
2020-02-28 14:13:30 -08:00
Stephen Neuendorffer c6f3fc4999 Revert "[MLIR] Add support for libMLIR.so"
This reverts commit 1246e86716.
2020-02-28 12:17:39 -08:00
Valentin Churavy 1246e86716 [MLIR] Add support for libMLIR.so
Putting this up mainly for discussion on
how this should be done. I am interested in MLIR from
the Julia side and we currently have a strong preference
to dynamically linking against the LLVM shared library,
and would like to have a MLIR shared library.

This patch adds a new cmake function add_mlir_library()
which accumulates a list of targets to be compiled into
libMLIR.so.  Note that not all libraries make sense to
be compiled into libMLIR.so.  In particular, we want
to avoid libraries which primarily exist to support
certain tools (such as mlir-opt and mlir-cpu-runner).

Note that the resulting libMLIR.so depends on LLVM, but
does not contain any LLVM components.  As a result, it
is necessary to link with libLLVM.so to avoid linkage
errors. So, libMLIR.so requires LLVM_BUILD_LLVM_DYLIB=on

FYI, Currently it appears that LLVM_LINK_LLVM_DYLIB is broken
because mlir-tblgen is linked against libLLVM.so and
and independent LLVM components

(updated by Stephen Neuendorffer)

Differential Revision: https://reviews.llvm.org/D73130
2020-02-28 11:35:19 -08:00
Stephen Neuendorffer 2f265e3528 [MLIR] Move from using target_link_libraries to LINK_LIBS for llvm libraries.
When compiling libLLVM.so, add_llvm_library() manipulates the link libraries
being used.  This means that when using add_llvm_library(), we need to pass
the list of libraries to be linked (using the LINK_LIBS keyword) instead of
using the standard target_link_libraries call.  This is preparation for
properly dealing with creating libMLIR.so as well.

Differential Revision: https://reviews.llvm.org/D74864
2020-02-28 11:35:17 -08:00
Stephen Neuendorffer c07fb9e016 [MLIR] Refactor library handling for conversions.
Collect a list of conversion libraries in cmake, so we don't have to
list these explicitly in most binaries.

Differential Revision: https://reviews.llvm.org/D75222
2020-02-28 11:35:17 -08:00
Stephen Neuendorffer 5869552821 [MLIR] Refactor handling of dialect libraries
Instead of creating extra libraries we don't really need, collect a
list of all dialects and use that instead.

Differential Revision: https://reviews.llvm.org/D75221
2020-02-28 11:35:16 -08:00
Stephen Neuendorffer 01b209679f [MLIR] add show-dialects option for mlir-opt
Display the list of dialects known to mlir-opt.  This is useful
for ensuring that linkage has happened correctly, for instance.

Differential Revision: https://reviews.llvm.org/D74865
2020-02-27 10:43:39 -08:00
Stephan Herhut 7a7eacc797 [MLIR][GPU] Implement a simple greedy loop mapper.
Summary:
The mapper assigns annotations to loop.parallel operations that
are compatible with the loop to gpu mapping pass. The outermost
loop uses the grid dimensions, followed by block dimensions. All
remaining loops are mapped to sequential loops.

Differential Revision: https://reviews.llvm.org/D74963
2020-02-25 11:42:42 +01:00
Lei Zhang 8358ddbe5d [mlir][spirv] NFC: Move test passes to test/lib
Previously C++ test passes for SPIR-V were put under
test/Dialect/SPIRV. Move them to test/lib/Dialect/SPIRV
to create a better structure.

Also fixed one of the test pass to use new
PassRegistration mechanism.

Differential Revision: https://reviews.llvm.org/D75066
2020-02-24 14:17:02 -05:00
Alexander Belyaev 284279ac23 [MLIR] Add naive fusion of parallel loops. 2020-02-19 14:51:09 +01:00
Diego Caballero d7058acc14 [mlir] Add MemRef filter to affine data copy optimization
This patch extends affine data copy optimization utility with an
optional memref filter argument. When the memref filter is used, data
copy optimization will only generate copies for such a memref.

Note: this patch is just porting the memref filter feature from Uday's
'hop' branch: https://github.com/bondhugula/llvm-project/tree/hop.

Reviewed By: bondhugula

Differential Revision: https://reviews.llvm.org/D74342
2020-02-14 13:41:45 -08:00
Denis Khalikov a062a3ed7f [mlir][spirv] Add ConvertGpuLaunchFuncToVulkanCallsPass
Implement a pass to convert gpu.launch_func op into a sequence of
Vulkan runtime calls. The Vulkan runtime API surface is huge so currently we
don't expose separate external functions in IR for each of them, instead we
expose a few external functions to wrapper libraries which manages
Vulkan runtime.

Differential Revision: https://reviews.llvm.org/D74549
2020-02-13 14:10:07 -05:00
Mehdi Amini 7b635880ab Fix MLIR build when the NVPTX target isn't configured
Differential Revision: https://reviews.llvm.org/D74472
2020-02-12 12:38:45 +00:00
Mehdi Amini c64770506b Remove static registration for dialects, and the "alwayslink" hack for passes
In the previous state, we were relying on forcing the linker to include
all libraries in the final binary and the global initializer to self-register
every piece of the system. This change help moving away from this model, and
allow users to compose pieces more freely. The current change is only "fixing"
the dialect registration and avoiding relying on "whole link" for the passes.
The translation is still relying on the global registry, and some refactoring
is needed to make this all more convenient.

Differential Revision: https://reviews.llvm.org/D74461
2020-02-12 09:13:02 +00:00
Marius Brehler a9a305716b [mlir] Revise naming of MLIROptMain and MLIRMlirOptLib
* Rename CMake target MLIROptMain to MLIROptLib:
   The target provides the main library
* Rename CMake target MLIRMlirOptLib to MLIRMlirOptMain:
   The target provides the main() entry function

At the moment, the Bazel configuration of TenorFlow maps the target
MlirOptLib to "lib/Support/MlirOptMain.cpp" and MlirOptMain to
"tools/mlir-opt/mlir-opt.cpp". This is the other way around in the CMake
configuration. As discussed in the context of the pull request
https://github.com/tensorflow/tensorflow/pull/36301, it seems useful to
revise the naming in the MLIR repo.

Differential Revision: https://reviews.llvm.org/D73778
2020-02-12 09:46:09 +01:00
Kern Handa 8dc3da7d58 [mlir] Build fix for mlir-opt
mlir-opt needs to link against MLIRLoopAnalysis
This shouldn't be needed but MLIR "hack" for
"whole-archive" linking is not compatible with
CMake transitive dependencies management.

Differential Revision: https://reviews.llvm.org/D74097
2020-02-06 05:16:01 +00:00
Stephan Herhut 921d4e7c8d [MLIR][GPU] Fix build files for mlir-opt.
The recent refactoring of build files broke building with the MIR CUDA
integration enabled. This fixes it by adding some additional
dependencies to mlir-opt.

Differential Revision: https://reviews.llvm.org/D74041
2020-02-05 17:13:48 +00:00
Stephen Neuendorffer d7cbef2714 [MLIR] Fixes for shared library dependencies.
Summary:

This patch is a step towards enabling BUILD_SHARED_LIBS=on, which
builds most libraries as DLLs instead of statically linked libraries.
The main effect of this is that incremental build times are greatly
reduced, since usually only one library need be relinked in response
to isolated code changes.

The bulk of this patch is fixing incorrect usage of cmake, where library
dependencies are listed under add_dependencies rather than under
target_link_libraries or under the LINK_LIBS tag.  Correct usage should be
like this:

add_dependencies(MLIRfoo MLIRfooIncGen)
target_link_libraries(MLIRfoo MLIRlib1 MLIRlib2)

A separate issue is that in cmake, dependencies between static libraries
are automatically included in dependencies.  In the above example, if MLIBlib1
depends on MLIRlib2, then it is sufficient to have only MLIRlib1 in the
target_link_libraries.  When compiling with shared libraries, it is necessary
to have both MLIRlib1 and MLIRlib2 specified if MLIRfoo uses symbols from both.

Reviewers: mravishankar, antiagainst, nicolasvasilache, vchuravy, inouehrs, mehdi_amini, jdoerfert

Reviewed By: nicolasvasilache, mehdi_amini

Subscribers: Joonsoo, merge_guards_bot, jholewinski, mgorny, mehdi_amini, rriddle, jpienaar, burmako, shauheen, antiagainst, csigg, arpith-jacob, mgester, lucyrfox, herhut, aartbik, liufengdb, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73653
2020-02-04 08:56:37 -08:00
Lei Zhang df71000d7d [mlir][spirv] Convert linalg.generic for reduction to SPIR-V ops
This commit adds a pattern to lower linalg.generic for reduction
to spv.GroupNonUniform* ops. Right now this only supports integer
reduction on 1-D input memref. Shader entry point ABI is queried
to make sure that the input memref's shape matches the local
workgroup's invocation configuration. This makes sure that the
workload fits in one local workgroup so that we can leverage
SPIR-V group non-uniform operations.

linglg.generic is a structured op that preserves the right level
of information. It is easier to recognize reduction at this level
than performing analysis on loops.

This commit also exposes `getElementPtr` in SPIRVLowering.h given
that it's a generally useful utility function.

Differential Revision: https://reviews.llvm.org/D73437
2020-01-31 09:37:04 -05:00
David Truby 63c8972562 [MLIR] Add OpenMP dialect with barrier operation
Summary:
Barrier is a simple operation that takes no arguments and returns
nothing, but implies a side effect (synchronization of all threads)

Reviewers: jdoerfert

Subscribers: mgorny, guansong, mehdi_amini, rriddle, jpienaar, burmako, shauheen, antiagainst, nicolasvasilache, arpith-jacob, mgester, lucyrfox, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72400
2020-01-29 11:34:58 +00:00
Mehdi Amini 308571074c Mass update the MLIR license header to mention "Part of the LLVM project"
This is an artifact from merging MLIR into LLVM, the file headers are
now aligned with the rest of the project.
2020-01-26 03:58:30 +00:00
Nicolas Vasilache 89b395fe79 [mlir][EDSC] Refactor dependencies involving EDSCs.
Summary: This diff removes the dependency of LinalgOps and VectorOps on EDSCs.

Reviewers: jpienaar, ftynse

Reviewed By: ftynse

Subscribers: merge_guards_bot, mgorny, mehdi_amini, rriddle, burmako, shauheen, antiagainst, csigg, arpith-jacob, mgester, lucyrfox, herhut, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72481
2020-01-15 09:34:29 -05:00
Lei Zhang b30d87a90b [mlir][spirv] Add basic definitions for supporting availability
SPIR-V has a few mechanisms to control op availability: version,
extension, and capabilities. These mechanisms are considered as
different availability classes.

This commit introduces basic definitions for modelling SPIR-V
availability classes. Specifically, an `Availability` class is
added to SPIRVBase.td, along with two subclasses: MinVersion
and MaxVersion for versioning. SPV_Op is extended to take a
list of `Availability`. Each `Availability` instance carries
information for generating op interfaces for the corresponding
availability class and also the concrete availability
requirements.

With the availability spec on ops, we can now auto-generate the
op interfaces of all SPIR-V availability classes and also
synthesize the op's implementations of these interfaces. The
interface generation is done via new TableGen backends
-gen-avail-interface-{decls|defs}. The op's implementation is
done via -gen-spirv-avail-impls.

Differential Revision: https://reviews.llvm.org/D71930
2019-12-27 16:25:09 -05:00
Mehdi Amini 56222a0694 Adjust License.txt file to use the LLVM license
PiperOrigin-RevId: 286906740
2019-12-23 15:33:37 -08:00
Nicolas Vasilache 5c0c51a997 Refactor dependencies to expose Vector transformations as patterns - NFC
This CL refactors some of the MLIR vector dependencies to allow decoupling VectorOps, vector analysis, vector transformations and vector conversions from each other.
This makes the system more modular and allows extracting VectorToVector into VectorTransforms that do not depend on vector conversions.

This refactoring exhibited a bunch of cyclic library dependencies that have been cleaned up.

PiperOrigin-RevId: 283660308
2019-12-03 17:52:10 -08:00
Nicolas Vasilache 6755543af5 Move Linalg Transforms that are actually Conversions - NFC
PiperOrigin-RevId: 281844602
2019-11-21 15:41:32 -08:00
Nicolas Vasilache fa14d4f6ab Implement unrolling of vector ops to finer-grained vector ops as a pattern.
This CL uses the pattern rewrite infrastructure to implement a simple VectorOps -> VectorOps legalization strategy to unroll coarse-grained vector operations into finer grained ones.
The transformation is written using local pattern rewrites to allow composition with other rewrites. It proceeds by iteratively introducing fake cast ops and cleaning canonicalizing or lowering them away where appropriate.

This is an example of writing transformations as compositions of local pattern rewrites that should enable us to make them significantly more declarative.

PiperOrigin-RevId: 281555100
2019-11-20 11:49:36 -08:00
Eric Schweitz 88368a19aa Add some CMake rules for installing headers, mlir-tblgen, and mlir-opt
Closes tensorflow/mlir#246

PiperOrigin-RevId: 281442685
2019-11-19 21:05:16 -08:00
Mahesh Ravishankar a78bd84cf8 NFC: Refactor Dialect Conversion targeting SPIR-V.
Refactoring the conversion from StandardOps/GPU dialect to SPIR-V
dialect:
1) Move the SPIRVTypeConversion and SPIRVOpLowering class into SPIR-V
   dialect.
2) Add header files that expose functions to add patterns for the
   dialects to SPIR-V lowering, as well as a pass that does the
   dialect to SPIR-V lowering.
3) Make SPIRVOpLowering derive from OpLowering class.
PiperOrigin-RevId: 280486871
2019-11-14 12:34:54 -08:00